This invention relates to the storage of spare tires or wheels under vehicles and, more particularly, to cable and drum type mechanisms by which a spare tire is supported in a stored position beneath the vehicle chassis and is lowerable from the stored position to an accessible position in which the tire engages the ground beneath the vehicle.
Mechanisms of the character to which the present invention relates have been provided heretofore and, generally, have included some form of a rod or pipe providing a reel or drum which is rotatable in opposite directions to provide for the winding and unwinding of a cable or other flexible connector relative thereto. Such cable or connector has a free end adapted to be releaseably interconnected with a spare tire and, when the cable is wound onto the drum, the spare tire is elevated into a storage position beneath the vehicle. Upon rotation of the drun in the opposite direction to unwind the cable, the spare tire is lowered to ground beneath the vehicle and, generally, is then pulled from beneath the vehicle and disconnected from the cable to enable use of the tire. Exemplative prior art devices of this character are shown in U.S. Pat. Nos. 1,983,767 to Mueller; 3,372,821 to Podhajsky; 3,539,152 to Paul; 3,542,413 to Hardison; and, 3,554,397 to Cluff.
The storage of a spare tire beneath the chassis of a vehicle is advantageous for a number of reasons including the optimizing of available storage space and the aesthetics of interior portions of the vehicle where spare tires are generally stored. Such storage also avoids having to physically lift the spare tire to remove it from within the vehicle and the potential soiling or damaging of the clothes of the person doing so.
While cable and drum type mechanisms heretofore available can provide these advantages, there are disadvantages with respect to the structure and operation of the prior mechanisms which have limited acceptability thereof. In PG,3 this respect, displacement of a spare tire from its stored position first requires unwinding rotation of the reel or drum to lower the tire into engagement with the ground beneath the vehicle. The tire must then be pulled rearwardly of the vehicle in order to achieve separation of the tire from the cable. Return of a replaced tire or a new spare tire to the stored position is achieved by reversing the above procedure and, generally, the tire with the cable reconnected thereto is first pushed into position under the vehicle before the drum or reel is rotated to rewind the cable thereonto. It will be appreciated that the elevating of the tire from the ground to its stored position imposes the greatest load on the reel or drum and accordingly requires the greatest exertion of force to rotate the reel or drum. In order to minimize the latter, the reel or drum in the mechanisms heretofore provided has been defined by a small diameter rod or tube so as to minimize the torque on the drum and thus the force required to rotate the drum in elevating the tire. While the small diameter rod serves its purpose in this respect, a considerable amount of excess cable is required to enable withdrawal of the spare tire outwardly from beneath the vehicle to achieve connection and disconnection of the cable from the spare tire and, accordingly, a considerable axial length of drum is required to accommodate the total length of cable, and a considerable amount of rotation of the drum is required to initially rewind the excess cable thereonto prior to the loading of the drum to elevate the tire from ground to its stored position. Additionally, the length of the drum creates problems with respect to mounting and operating the mechanism, especially in small vehicles. While the length of the reel or drum can be reduced by providing for the convolutions of cable to be wound on top of one another like a fishing reel, the latter defeats the purpose of the small diameter drum. In this respect, when the excess cable has been wound onto the drum to the point where the tire is to be elevated from ground, the build-up of cable has positioned the latter a considerable distance radially outwardly of the drum axis, thus increasing the torque on the drum and the force required to rotate the latter to elevate the tire.